Mclaneinc Posted December 30, 2019 Share Posted December 30, 2019 No power light, No drive movement ,PSU tested on others and fine.. Where do I start guts, voltage reg on the side? Caps are not bloated.. Any idea's would be appreciated... I've not swapped the drive mech as the board isn't even powering on and I also am worried about killing the mech if there's a major fault on the actual main board.. As most people know, I'm not very electronic (yeah weird as I ran an electronics shop) BUT can use a multimeter, can solder and can follow instruction. Quote Link to comment Share on other sites More sharing options...
ivop Posted December 30, 2019 Share Posted December 30, 2019 First thing I would do is check the 5V and 12V regulators with a multimeter. 1 Quote Link to comment Share on other sites More sharing options...
Mclaneinc Posted December 30, 2019 Author Share Posted December 30, 2019 (edited) okey doke, that's centre and outside right leg if I remember rightly? Begging its them as they are dead cheap...But both going at the same time? I'll get my meter out in a sec Edited December 30, 2019 by Mclaneinc Quote Link to comment Share on other sites More sharing options...
+kheller2 Posted December 30, 2019 Share Posted December 30, 2019 Start with the complete FSM section 4-5 Quote Link to comment Share on other sites More sharing options...
xrbrevin Posted December 30, 2019 Share Posted December 30, 2019 i would go straight to the power circuit diagram in the manual and test from 9VAC onwards Quote Link to comment Share on other sites More sharing options...
+Nezgar Posted December 30, 2019 Share Posted December 30, 2019 If you turn on the drive, do you feel the heat sink on the left or the right heat up significantly after even 10 seconds or so? That would be an immediate sign of a short after the regulator output, which was the symptom in a drive I repaired which was caused by a shorting capacitor: https://atariage.com/forums/topic/286826-1050-12v-issue/ 5V regulator is Q7 at the back right of the drive by the drive select switch. 12V regulator is Q8 at the back left of the drive by the power jack. Rather than manoeuvring the probes on the tiny legs of the regulators directly, you can use these test points: TP13 is the 5V output rail TP14 is the 12V output rail. If you're getting 0V on the INPUT to the regulators, one of those 3 big caps or the rectifier diodes may be dead. If you're getting lower than 5V or 12V on the outputs, one or more of the small capacitors in the back section of the board may be dead. (C42, C43, C44, C51) Since you have no power LED, i'd focus on the the 7805 regulator (Q7) side first. 1 Quote Link to comment Share on other sites More sharing options...
Mclaneinc Posted December 30, 2019 Author Share Posted December 30, 2019 You have saved me a type, the heatsink is bloody hot straight away and although I've not used the test points I struggled with the probes and getting pretty much zero out of both regs.. ack, didn't check the input voltages...Will do that in the morn... Big thank you to you and all the people offering help, I looked at the FSM and it started talking wave forms etc which I don't have a scope and even if I did I would be totally lost.. Will come back to it in the morn, have to attend family business now...Joy of joys...:( Quote Link to comment Share on other sites More sharing options...
xrbrevin Posted December 30, 2019 Share Posted December 30, 2019 scope not usually essential so bypass those details for now. its possible 1 or both of the voltage regs have failed, resulting in instant heatsink heat the smaller electrolytic cap C70 can fail and give the symptoms you suggest. worth a check of the 2x diodes between the big caps with a mul-timeter. also check continuity/voltage at the switch Quote Link to comment Share on other sites More sharing options...
Mclaneinc Posted December 30, 2019 Author Share Posted December 30, 2019 (edited) Didn't know where the TP's where so googled, nowt out on either TP, will order a 7812 and a 7805 and the cap you mention... Ta guys..More when things have been replaced.. Sorry, what is the value of C70, I think its 47uf 16v but its got a mark on it. Also is it worth getting a TIP110 as its all on the same sink...? Remember, I'm not electronically skilled as if it wasn't obvious enough, its been a long time since I did anything much more that checking continuity, so bare with me..I can recognise components, read resistor values and stuff like that but building kits is painting by numbers for me and I knew orientation of components, things like the 48K upgrades were easy because it was detailed out but electronic theory etc is not something I learned.. Should have already left but wanted to pass back as much info as possible, didn't check the switch because the board gets hot only when the switch is on so presumed it was working.. Oh oh, wife looking at me with that "you are in trouble" look...I'm orf.. Edited December 30, 2019 by Mclaneinc 1 1 Quote Link to comment Share on other sites More sharing options...
+Nezgar Posted December 30, 2019 Share Posted December 30, 2019 The darlington transistor (the 3rd thing attached to the heatsink that looks like a voltage regulator) is only used to stabilize the RPM of the disk, to ensure it stays on spec, and will increase/decrease power to the motor to maintain the correct speed. I wouldn't worry about that. Schematics indeed show C70 as 47μf, 16V. Quote Link to comment Share on other sites More sharing options...
Kyle22 Posted December 31, 2019 Share Posted December 31, 2019 (edited) Also, please check the diodes in the power supply section. They *DO* go bad. They are known to overheat. Replace them with long legs so they stand high above the board. More airflow = more cooling. Edit: typo. Edited December 31, 2019 by Kyle22 1 Quote Link to comment Share on other sites More sharing options...
Mclaneinc Posted December 31, 2019 Author Share Posted December 31, 2019 I checked the diodes with the multimeter in diode mode and one way was reading 548-558 and the reverse was going to one, sometimes after the display climbed for a sec or two...Does that sound correct? Sorry about being thick on this stuff... And thanks for the C70 clarification, new year shopping has put a damper on getting the gear as most online retailers want you to buy packs or have an account, I live not too far from Cricklewood electronics so will pop there in the week... Quote Link to comment Share on other sites More sharing options...
TGB1718 Posted December 31, 2019 Share Posted December 31, 2019 (edited) Checking any component while in circuit can prove difficult due to parallel circuit paths, if your not sure try to unsolder and lift one leg of the diode. The climb of the meter is probably due to capacitors in the circuit, hence lift one leg if possible. Edited December 31, 2019 by TGB1718 1 Quote Link to comment Share on other sites More sharing options...
xrbrevin Posted December 31, 2019 Share Posted December 31, 2019 when the C70 cap was faulty in my drive, i used the continuity check and it read in situ as a dead short. good caps usually give an ascending reading before stopping - i guess that its taking charge from the meter 1 Quote Link to comment Share on other sites More sharing options...
Mclaneinc Posted December 31, 2019 Author Share Posted December 31, 2019 (edited) Thanks for the info, I had read in a frantic google search to try and not do it in situ or at least make sure the caps are fully discharged.. Will get the parts, not got the machine in front of me at this sec, what are the diodes, 1N4001's? (this is from shop memory of my stock then) I'll recheck later and add them to the shopping list just to give the old beast a service of sorts.. Wife tidying the bedroom / man cave so I've had to put the gear out of the way... She is, she who must be obeyed Last thing I want is her touching the board while statically charged up from hoovering Getting a little nervous, not used a soldering iron in anger in AGES, time to make sure my glasses are fine Edited December 31, 2019 by Mclaneinc Quote Link to comment Share on other sites More sharing options...
TGB1718 Posted December 31, 2019 Share Posted December 31, 2019 If your not wanting to desolder stuff, have you a second working drive, make measurements there and note the readings, then compare with the faulty drive, might give you some clues before starting to dismantle it. Quote Link to comment Share on other sites More sharing options...
Mclaneinc Posted December 31, 2019 Author Share Posted December 31, 2019 My man cave is now a bit of a mess, 3 1050's in various stages of nakedness and now a small issue with a gotek drive where the original real 1.44mb drive had a 3 pin lead on a 4 pin connector and it all seems reversed on the gotek... At least I can find pin one on the IDE header on the gotek but the psu for the drive lead can only fit one way as normal but its only on 3 pins, hoping I don't kill the bugger. Wasn't expecting the drive until next week but it came today and while I'm stuck waiting to get the 1050 parts I thought I'd play with it... And guess who pulled the fdd lead off the real drive and didn't spot it wasn't on all four pins......Between all this and some idiot reversing in to my car yesterday (luckily no damage) I'm having a confusing set of days Quote Link to comment Share on other sites More sharing options...
ChildOfCv Posted December 31, 2019 Share Posted December 31, 2019 The other important thing to look for with capacitors is if they've leaked out on the board. If you see stains around any of the caps, one or more have failed and need to be replaced, and that liquid is also corrosive so clean it up completely. Quote Link to comment Share on other sites More sharing options...
TGB1718 Posted January 1, 2020 Share Posted January 1, 2020 Some years ago I became aware of the potential capacitor problem with 1050's and although both mine were working there were extended periods (years) when I didn't use them, so as a matter of course I ordered 2 full sets of capacitors and replaced the lot on both drives, didn't cost much nor did it take that long to do, so hopefully mine won't suffer from capacitor issues. Quote Link to comment Share on other sites More sharing options...
Mclaneinc Posted January 1, 2020 Author Share Posted January 1, 2020 As said, the caps all look fine, no splits, deforming or the usual suspect but why they used some sort of glue around the 3 big cans mystifies me, I thought it was seepage at first. Was thinking of doing a full recapping, got a set for my old Amiga 1200 to do as well..Will get the components to eliminate the fault (hopefully) on the 1050 and then go from there. Happy new year to all.. Quote Link to comment Share on other sites More sharing options...
+DrVenkman Posted January 1, 2020 Share Posted January 1, 2020 2 hours ago, Mclaneinc said: but why they used some sort of glue around the 3 big cans mystifies me You see this a lot in vintage electronics. It’s for physical shock (not electrical shock) protection - those big caps are relatively heavy and attached by only two thin leads. If there’s the slightest space between the bottom of the cap and the board, those will be nudged and shift as a result of their own weight during shipping and potentially crack the solder joints or damage the caps. It can usually be removed pretty easily with isopropyl alcohol and/or low heat from a heat gun. Quote Link to comment Share on other sites More sharing options...
Mclaneinc Posted January 1, 2020 Author Share Posted January 1, 2020 Ah, doc, thank you...Last request (for the moment) is the 2 long leg diodes between the cans, part no brings up nothing but I think (?) they are simple rectifier diodes, could a 1n4001 be used ? If not exact replacement equivs would be appreciated so I can get the order in. As I say, I'm not really electronic minded so all help appreciated.. Quote Link to comment Share on other sites More sharing options...
Mclaneinc Posted January 1, 2020 Author Share Posted January 1, 2020 Right, most parts ordered, should be here monday ish..Didn't order the diodes as yet, lets see what these parts do... Quote Link to comment Share on other sites More sharing options...
BillC Posted January 1, 2020 Share Posted January 1, 2020 (edited) 3 hours ago, Mclaneinc said: Ah, doc, thank you...Last request (for the moment) is the 2 long leg diodes between the cans, part no brings up nothing but I think (?) they are simple rectifier diodes, could a 1n4001 be used ? If not exact replacement equivs would be appreciated so I can get the order in. As I say, I'm not really electronic minded so all help appreciated.. I checked the 810FSM, and the main rectifier diodes are listed as MR501 which are rated at 3A. The other diodes are either 1n4001(1A) or 1n914(200mA). I would not recommend using 1n4001 diodes in the rectifier bridge since they aren't rated for sufficient current, 1n4001 is the part listed for the voltage doubler circuit. The MR852G and 1n5401 appear to be better options for the main rectifier bridge. Edited January 1, 2020 by BillC Quote Link to comment Share on other sites More sharing options...
Mclaneinc Posted January 1, 2020 Author Share Posted January 1, 2020 Just I'm clear here Bill, are you talking about the bigger set of diodes at the back left as per the 1N5401, if yes then I'd not really given them any thought, I only thought of those two between the cans and does that mean the 1n4001 are ok for the two between the cans? Sorry, just want to order the right stuff And I really appreciate the help!!! Quote Link to comment Share on other sites More sharing options...
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