SM124 Monitor

[Smithers]

Hello all

I just wished to ask some advice please? I have an ST520 FM which I used at music college in the mid 1990's to run Cubase 3.1 Score. I recently got it out of the attic and bought a colour monitor and a SM125 monitor to run Cubase to set up my retro music room again. Unfortunately the 125 died.... input cap I have read and not a difficult fix  .. but I don't have the skills to fix it, so I managed to find an SM124 at a great price. I know that you should turn on the monitor first and switch off last...but I have a monitor master switch unit... 

My question is.... can the Monitor Master cause strain on the voltage going into the monitors when switching between them? Or is it just a passive switching device? 

I only use the ST for Cubase really.

 

Thanks for any advice guys, I am not a tech person. 

 

Cheers 👍 

[Shredder11]

I used a "Monitor Master" switch box for years and years with zero issues and nothing broken in the slightest.  I still have a spare as I bought a couple of them back then.

[atarian1]

• Turn off the computer first.
• Press the button on the Monitor Master to switch monitor.
• Turn on the computer again.

I don't recommend pushing the button on the Monitor Master while the computer is on to switch monitors. I see no circuitry inside that makes it look like an "intelligent" device. The only device off the top of my head that did allow this was the Astra SW-1. 

[JamesWD]

Colour/Mono switchboxes just toggled the mono detect line which causes a cold boot by design so not an issue.

 

Then again this stuff is 35 years old so just switching the thing on could cause  . . . 

Edited October 10, 2022 by JamesWD

[Smithers]

Thanks for the advice guys, it is really appreciated. It could well be that I switched the ST on first mistakenly after a couple of beers which blew the input Cap, DOH! 🥰 As I said, I am just a thick musician! 

I think to be on the safe side I will just put the Monitor Master aside for now and follow the correct on/off procedure in future when I get the SM124. I think I won a good bid for £30, the guy seems really genuine and has 100% eBay rating for his Atari store.

Having a few problems setting up an HDD I bought a while back. It is an aftermarket 200mB jobbie but it does work fine and the ST recognises it.

I downloaded a great PDF explaining everything in detail but it may as well be in Swaheli for all I understand. Formatting and partitioning etc. So I will likely start a knew thread asking for help soon for a layman.

 

Thanks again guys 😉👍👍

 

Smithers 

[Smithers]

PS - Sorry to bang on, but I am definitely keeping the SM125 and not binning it. 

 

I had taken it to my Marshall Amp repair guru who replaced the input voltage Cap, the one that normally blows first, it is 2.7 micro Farad (I think). The monitor worked for a while then just went off again, but the LED light worked so at least power was going to the unit. I took it back but he said it was out of his knowledge range.

 

Now... after some research I have heard that if you just replace the blown electrolytic cap like for like it is likely to go again soon and you are better off upgrading to a polymer Cap replacement. This would explain... but the led light does not come on now.. 

So I am hoping it just needs a polymer Cap replacement and a new fuse on the inside. I can't see any burn or corrosion on the copper Power Supply transformer wires when I took the back off. It is all very clean and dust free and no burning smell. But I am not going to attempt to fix it myself.

 

Thanks 👍 😊 

[JamesWD]

Find someone who is ok with a soldering iron, I had a SC1224 colour monitor that went bang a few months back, it turned out a cap had blown on the PSU board so replaced them all anyways. If it had been an issue on the main board with all the high voltages then i don't know what i'd do.

 

Not sure if SM125 has its own PSU board like the SC1224 but if it does makes repair alot easier, just take lots of pics so you know where everything plugs in 

[Smithers]

Thanks James, it's normally the old 35 year old electrolytic Caps that blow on these units. It's fluid inside so will deteriate over time I guess. A bit like Lead Acid car batteries vs Lithium in modern cars. 

I have an SC1224 and works fine still but not much of a gamer although my 16 year old nephew loves the retro stuff.. 

Hopefully the SM124 will arrive without any issues and work with Cubase. I actually prefer the 124 to the 125 the look and casing. Taken a bit of a gamble buying an old monitor on the Internet... but Hey? For 30 quid worth a punt 😉👍

 

I will put the 125 away for the time being and hopefully find an old CRT TV repair guy in time who can do the fix with a modern solid state Cap for not to much money. 👍 

 

Thanks for the advice James, take care mate.

Smithers 😉👍