VOGONS


First post, by Simon

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I have a compaq p1220 which is just a rebadged mitsubushi 2060u.

It stopped working one day and now just flashes the amber standby light. I have tried new vga cables, power cables, graphics cards, praying, leaving it off for a day. But none of this worked it just flashes away.

It was a great crt monitor so i want it fixed.

I made this post here

http://www.network54.com/Forum/87612/thread/1 … itsubishi+2060u

But I no longer no my login details or what he is talking about.

But I know someone use to chip playstations so he should be able to do any soldering work for me.

The reply i got on that forum said
"Q502, Q503, and Q504. I also replaced C508"

What is this referring to and where are they located and where can i buy these parts? I am in the uk so a uk vendor would be best.

I can provide internal pictures if requested just let me know what area you want to see.

Reply 1 of 9, by Tetrium

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Maybe the location of caps he replaced???

Whats missing in your collections?
My retro rigs (old topic)
Interesting Vogons threads (links to Vogonswiki)
Report spammers here!

Reply 2 of 9, by sklawz

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hi

the items listed as Q are most likely
transistors. the transistor type is
unknown and you would need to inspect
the board. the C is a capacitor.

it's worth mentioning that it's
hazardous inside a CRT and you
should be careful.

bye

Reply 3 of 9, by Old Thrashbarg

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That's all part of the horizontal deflection circuitry. Q502 looks to be the horizontal output transistor, a 2SC5516. Q503 and Q504 are part of the distortion compensation circuit, which controls the horizontal size and geometry... Q503 is an ET453 FET that serves basically as a ripple filter, and Q504 is the output, a 2SJ512. I'm not sure where C508 is, I'd assume it's probably upstream somewhere...

Here's the service manual for the thing.

Reply 4 of 9, by Simon

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Wow thanks old thrashbag I am sure that service manual will come in handy.

I have uploaded some pictures here

http://www.mike65.ukfsn.org/main/uploads/files/crt2/

I suck at taking photos but in 5390 those three resistors have burn marks around them. The board its self is where all the power goes before it goes any where else.

Are they the bad components and need replacing? Or do did they fail because something else went wrong?

They are R992, R941 and R923.

Thats the only visual damage I could see but with solid state electronics I doubt the damage is always visible.

Reply 5 of 9, by Old Thrashbarg

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Yeah, that's definitely a problem around those three resistors. Pull 'em and check 'em... they should be 22Kohm each. Also test diode D904. If any of those test bad, replace them. But the resistors themselves don't look burned, so I'm thinking it might have been cracked solder joints that caused it... if they test good, then resoldering them would probably do the trick.

And though the manual doesn't make it exactly clear, it appears that the output coming off of those resistors is regulated down into the 215V feed going into the horizontal section. So there's still a pretty good possibility that Q502, Q503 and Q504 could be toasted.

Reply 8 of 9, by Simon

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I am going to borrow a fluke multimeter and check them. Where can I buy the replacement resistors and Q502, Q503 and Q504? They look like little black transistors.

I checked the connector and there was no burn marks on either of them.

Reply 9 of 9, by h-a-l-9000

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Well could have been - these white connectors have a habit of going bad and then the horizontal output stage breaks.

Unfortunately there is no complete schematic in this service manual, so its of limited use.

Have a look at section 1.7.7 LED display, does the LED flash like that? Or is there a zip-zip-zip sound when the LED flashes?

As to the part numbers, have a look at the parts list in the service maual:

502 CP260P43105 TRANSISTOR 2SC5516005M1
503 CP260P33402 TRANSISTOR ET453MR-F143
504 CP260P42302 MOS-FET 2SJ512-LB107

This is the horizontal output stage and probably some of its supply transistors.
The 2SC5516 is on Ebay, I couldn't find it in my usual sources. The 2SJ512 is nothing special. The ET453MR may be.

1+1=10