Monitor Repair

[november]

This does not pertain to an aracde monitor but it's the same principle.


I have a couple monitors at a jobsite that need to be repaired and I have yet to get information on them, but I was told that some of the capacitors are burnt/black.

I assume that they need new capacitors.  If that's the case is it just as simple as taking 1 off and putting 1 on?  If I can get it to power on what symptoms should I look for to help me diagnose what the problem is?

[grantspain]

until you do some basic checks it is difficult to say what is the problem.
burnt capacitors is a quite worrying thing from my point of view.

best to check input voltage,check the chassis for bad solder joints and then inspect the chassis for these burnt components

i have had a few chassis with burnt caps,they were high voltage caps-one was on the mains input and the other was on the collector of the horizontal output transistor which was also faulty

[november]

When creating my post I wasn't even sure how/what to ask.  It's been ages since I've messed with electronics aside from car audio but it never hurts to start it up again.

When I get one of these monitors I will open it up and take a look.  I use my meter to check for resistance and what not.  But I really do not recall what type of reading I should get from caps.

Is there an online resource that you/anyone may be familiar with? 

[grantspain]

to read a capacitor you need a capacitance meter otherwise you will not get an accurate reading
normally if i get a monitor fault i start be using a multimeter to prove the mains voltage is correct and present,being in the u.s you would be looking at around 120vac
if thats o.k then the next thing to look at is if the screen flashes when you switch it off,the screen volts on the flyback transformer has any effect on the picture at all when adjusted or if  there is a orange glow from the tube neck near the neck card-5 minute job to do the lot.

if none of that can be proved i then look at the solder side of the chassis to check for bad solder connections

after that i check for any obvious component that have fried or in the case of an electrolitic capacitor bulged

after these checks you are then entering the realms of test point checks,whereby you would make voltage checks at various points with the aid of a schematic diagram

also worth listening to see if the chassis is trying to start,this will be either a ticking noise or a whistle-normally this will point towards a problem in the power supply circuit or the deflection circuit(horizontal output transistor being a very common problem)

worth noting that many monitors with a failure in the vertical frame circuit will refuse to start

other checks of course are the chassis fuse and visual inspection of the flyback transformer for cracks or damage including signs of arcing

monitors can be real pigs to fix,i have worked in the arcade industry for 22 years and have quite some knowledge of monitors(not the same league as ken,rick or qrz though)-i get some real problems from time to time(like the neotec 2702 i am working on now)

best of luck

[november]

Thank you for your input.  I'll use this info to start checking on the monitors from the site and  my own (my cab is complete just need wiring to the jamma harness).