+adamantyr Posted October 22, 2019 Share Posted October 22, 2019 So I was testing another console, using the power supply and monitor for my original TI setup, and when I plugged it back in, I didn't get my master title screen. Instead I got a black screen and the start-up sound long and drawn out forever... I have spare consoles, so I'm not too broken up, but this TI and I have been through a lot together. If such is a repairable item, I'd like to try. Anyone have any ideas what would cause that? VDP? ROM chips? Adam Quote Link to comment Share on other sites More sharing options...
HOME AUTOMATION Posted October 22, 2019 Share Posted October 22, 2019 Yep! Sorry though. Quote Link to comment Share on other sites More sharing options...
+adamantyr Posted October 22, 2019 Author Share Posted October 22, 2019 3 minutes ago, HOME AUTOMATION said: Yep! Sorry though. Yep what? That you know what's wrong? Quote Link to comment Share on other sites More sharing options...
HOME AUTOMATION Posted October 22, 2019 Share Posted October 22, 2019 VDP? ROM chips? That's 2 down... ... 38 to go! P.S. I've been in that boat myself, for some time now! Quote Link to comment Share on other sites More sharing options...
Shift838 Posted October 22, 2019 Share Posted October 22, 2019 1 hour ago, adamantyr said: So I was testing another console, using the power supply and monitor for my original TI setup, and when I plugged it back in, I didn't get my master title screen. Instead I got a black screen and the start-up sound long and drawn out forever... I have spare consoles, so I'm not too broken up, but this TI and I have been through a lot together. If such is a repairable item, I'd like to try. Anyone have any ideas what would cause that? VDP? ROM chips? Adam You can try to pull the 2156, 2157, and sound chip if they are socketed. The title screen is actually in the 2155 GROM chip, if i recall. If a GROM or sound chip has bit the dust then it can hold the bus down and cause the black screen and endless tone. Quote Link to comment Share on other sites More sharing options...
+adamantyr Posted October 22, 2019 Author Share Posted October 22, 2019 8 minutes ago, Shift838 said: You can try to pull the 2156, 2157, and sound chip if they are socketed. The title screen is actually in the 2155 GROM chip, if i recall. If a GROM or sound chip has bit the dust then it can hold the bus down and cause the black screen and endless tone. Thank you! I could always replace those from another console potentially. Quote Link to comment Share on other sites More sharing options...
HOME AUTOMATION Posted October 22, 2019 Share Posted October 22, 2019 (edited) A few thoughts... 1. Is there no chance you mixed up the transformer with another? Once I had an issue where a transformer only worked with certain consoles! 2. Maybe the the contacts in the plug were enlarged? 3. Were you using a CRT... Maybe static discharge got it! You should really check the power supply before doing any desoldering. If voltage drops too far when the TI is powered on, through no fault of the power supply, perhaps tracing the current path will lead you to the fault. ...also leave power on and check for excessive heating of components, or lack thereof? ...don't burn finger! Edited October 22, 2019 by HOME AUTOMATION Quote Link to comment Share on other sites More sharing options...
Sid1968 Posted October 22, 2019 Share Posted October 22, 2019 (edited) 14 hours ago, adamantyr said: So I was testing another console, using the power supply and monitor for my original TI setup, and when I plugged it back in, I didn't get my master title screen. Instead I got a black screen and the start-up sound long and drawn out forever... I have spare consoles, so I'm not too broken up, but this TI and I have been through a lot together. If such is a repairable item, I'd like to try. Anyone have any ideas what would cause that? VDP? ROM chips? Adam That could be a very simple problem. The Trafo (Your black box). The only thing that can get busted inside it are the two anti-surge fuses. The two anti-surge fuses in the Trafo-Model T40/E have 200 mA = 0,2 A and 500 mA = 0,5 A. They are very cheap to get. If you have a second Trafo try if the error is gone or just replace the two anti-surge fuses. Make it on your own risk. Edited October 22, 2019 by Sid1968 Quote Link to comment Share on other sites More sharing options...
+adamantyr Posted October 22, 2019 Author Share Posted October 22, 2019 9 hours ago, HOME AUTOMATION said: A few thoughts... 1. Is there no chance you mixed up the transformer with another? Once I had an issue where a transformer only worked with certain consoles! 2. Maybe the the contacts in the plug were enlarged? 3. Were you using a CRT... Maybe static discharge got it! You should really check the power supply before doing any desoldering. If voltage drops too far when the TI is powered on, through no fault of the power supply, perhaps tracing the current path will lead you to the fault. ...also leave power on and check for excessive heating of components, or lack thereof? ...don't burn finger! I wasn't doing anything to my original console. It was sitting on the desk, I unplugged power and monitor cable to use on another TI, then I plugged the original back in and it was fried. (I smelled a heated plastic smell, so something is probably melted.) 1 hour ago, Sid1968 said: That could be a very simple problem. The Trafo (Your black box). The only thing that can get busted inside it are the two anti-surge fuses. The two anti-surge fuses in the Trafo-Model T40/E have 200 mA = 0,2 A and 500 mA = 0,5 A. They are very cheap to get. If you have a second Trafo try if the error is gone or just replace the two anti-surge fuses. Make it on your own risk. I'm not a hardware guy. I was able to, at most, install an F18A in one console and swap a keyboard. I have no soldering iron or any electronic experience, nor do I want it. I'm pretty sure I'd burn the house down, or set one of my cats on fire. 1 Quote Link to comment Share on other sites More sharing options...
Asmusr Posted October 22, 2019 Share Posted October 22, 2019 If the console is making sound it has power, right? Quote Link to comment Share on other sites More sharing options...
+adamantyr Posted October 22, 2019 Author Share Posted October 22, 2019 56 minutes ago, Asmusr said: If the console is making sound it has power, right? Yeah, it gets power. I haven't cracked it open yet to investigate further, I may do so tonight. Quote Link to comment Share on other sites More sharing options...
Sid1968 Posted October 22, 2019 Share Posted October 22, 2019 2 minutes ago, adamantyr said: Yeah, it gets power. I haven't cracked it open yet to investigate further, I may do so tonight. You have that problem after using the Trafo on another TI, right? So its possible that the Trafo got damaged. You should check that. Already measured if the right Voltages lays on the board? Quote Link to comment Share on other sites More sharing options...
apersson850 Posted October 22, 2019 Share Posted October 22, 2019 The only chip I've ever had to replace in my original TI 99/4A is the PSI, the TMS 9901. My console has seen a lot of running hours, for sure. Quote Link to comment Share on other sites More sharing options...
+adamantyr Posted October 22, 2019 Author Share Posted October 22, 2019 Yeah it may just be one bad chip, which can be replaced. I plugged in one of my spare consoles and I'm back in business. Not sure what "tranfo" means, the power supply is fine, if that's what you're asking. It worked with the spare console and the console I was testing with. Quote Link to comment Share on other sites More sharing options...
Airshack Posted October 23, 2019 Share Posted October 23, 2019 They may be talking about the Transformer. The transformer is the small black box which plugs in between the computer and the electrical outlet. The power supply is inside the console. The transformer is sealed and external(the brick), while the power supply is inside the computer and easily accessible. 1 Quote Link to comment Share on other sites More sharing options...
Sid1968 Posted October 23, 2019 Share Posted October 23, 2019 (edited) 6 hours ago, Airshack said: They may be talking about the Transformer. The transformer is the small black box which plugs in between the computer and the electrical outlet. The power supply is inside the console. The transformer is sealed and external(the brick), while the power supply is inside the computer and easily accessible. Absolutely right. Obviously the Transformer (Trafo) was not the problem. But a faulty TMS 9901 could show a more serious problem... a Voltageproblem. The TI-99/4A has two boards inside. The big mainboard and the small Powersupply (PSU) Board. The Mainboard is connected to the PSU-Board with a cable. The connector on the PSU-Board is labled with +5V /Ground/12V/-5V. If this would be my TI-99/4A i would measure if that Voltages are correct and if all needed Voltages are correct on the mainboard too!!! If not its necessary to do this... I know that the changeing of Elecrolytic Capacitors is a strange thing in this Community. But you really should expose with that theme. To have a second mind of that look at the fabulous youtubechannel of this man: Click me! He often repairs Retrocomputers among others by changing one or better all elecrolytic capacitors. I peronally change the electrolytic capacitors each time i get an old machine to PREVENT damages on chips. Thats inexpensive and preserved me till now for "bad surprises". If you cant do it by yourself, find a buddy or a Professional who helps you. Cheers Sid Edited October 23, 2019 by Sid1968 1 Quote Link to comment Share on other sites More sharing options...
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