Jump to content
Due to a large amount of spamers, accounts will now have to be approved by the Admins so please be patient. ×
IGNORED

Peter Chou Power Supply F10214288


Recommended Posts

This power supply is out of my Mortal Kombat 1 LAI Cabinet.

 

Problem:

 

+5 and +12 are ok but -5 was reading 2.36 with or without load on power supply

 

Repairs

 

2 Diodes D12 and D13 and replaced 4 rail caps

 

Found this problem last night when playing MK2. Sound would start getting static and fading away and coming back. Checked power supply and found that -5 was very low causing my sound issue.

 

Having a look inside the power supply look like some of the rail caps where a bit old . Removed 2 1000uf and 2 3300uf and found all 4 to be a very low so i replaced all 4 with new ones no change.

 

Traced the -5 rail back L1 coil which goes into 2 PR1504 diodes. Removed these 2 diodes which showed the fault. One was open and the other was reading both ways. Replaced these with 2 i had spare out of a damaged power supply repaired the power supply.

Link to comment
Share on other sites

Just a quick note on replacing caps in switchmode power supplies; make sure you use "Low ESR" types. These are often brown (or black) in colour instead of the usual blue. Using "regular" type capacitors in switchmode supplies can lead to premature failure.
Link to comment
Share on other sites

  • Administrators
These are often brown (or black) in colour instead of the usual blue.

 

Not really an accurate statement. Yes you should use low Z caps, but I have plenty of esr caps of almost every colour, blue, black, brown, gold, white etc. The codes on the side of the caps will actually tell you what they are if you know the manufacturers production codes though.

Link to comment
Share on other sites

True, don't want to be called a colourist! What I was getting at is that the ones you buy at Altronics, DSE & Jaycar are often blue. (and only 85 degree, instead of the more rugged 105 degree type)

 

There's even more to than that when you get into the nitty gritties. Some switching regulators need very specific capacitors. Too low an ESR value is just as bad as too high and leads to instability. It's no wonder there are so many shit design power supplies out there!

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...