RE: Another K6100 HV question

Following up:

This is a P329 version board (with the HV cutoff), deflection has a LV2000
in it, the HV input at P900 is +/- 26v which is a bit low for the reference
values, I am keeping that in mind.

I have replaced:

Q901 & Q902 (MPSA06)

Q903 (2n3904)

Q900 (with a BU406D)

ZD901 (1n4743)

All the caps

I am getting HV (crackle, but can't find my HV probe to verify what it is
at).

B+ is 216v and adjusting the pot doesn't make any difference. From the FAQ
I have gone through everything it suggests for all the no effect:

Verified R912, R902 & R915 in circuit values all seem correct.

I have checked R901 - 906 in circuit and all seem ok.

Game in self-test.

At R904 where it connects to Q901 & Q902 the schematic says 6.9v I am
getting 23.1.

At Q900:

Base (reference 6.5) I get 14.5

Emitter (ref 6.0) I get 13.9

Collector is ~ 25v (close to right)

At ZD902 (150v zener) the reference is 33.7 and I have 57. The other side
which should be 181 is 216.

Voltages near Q906 (the BU207) are all within reasonable given the slightly
lower input voltages.

I was thinking possibly D901 or D902 is bad but I don't know what to replace
it with. I saw a reference to FR156 (which is only available from bob
Roberts) are there any other suggestions for replacing the ERC27-13?

Anyone know if I am totally off base here?

Thanks,

David

From: owner-vectorlist@vectorlist.org
[mailto:owner-vectorlist@vectorlist.org] On Behalf Of David Shoemaker
Sent: Sunday, October 09, 2011 2:41 PM
To: vectorlist@vectorlist.org
Subject: RE: VECTOR: Another K6100 HV question

Good page, I dug around on it a bit and noticed your also missing a source
for Q905 (2n6557 obsolete). As far as I can see the suggested replacement
is MJE15030 but it requires either a board mod or leg crossing.

And BU207 (Q906).

From: owner-vectorlist@vectorlist.org
[mailto:owner-vectorlist@vectorlist.org] On Behalf Of William Boucher
Sent: Sunday, October 09, 2011 9:23 AM
To: vectorlist@vectorlist.org
Subject: Re: VECTOR: Another K6100 HV question

Lots of good folks already answered your question but just in case...

I have a list of replacement parts for the wg6100 on a webpage here:

http://www.biltronix.com/arcade_electcomp_01.html#wg6100_rebuild_parts

This list includes the 150V zener as this

 
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=1N5383BRLGO
SCT-ND

Looks like I neglected to show a source for Q900. I'll have to fix that.

William Boucher
http://www.biltronix.com

----- Original Message -----

From: David Shoemaker <mailto:davids@oz.net>

To: vectorlist@vectorlist.org

Sent: Sunday, October 09, 2011 1:05 AM

Subject: VECTOR: Another K6100 HV question

As I was on a roll I figured I would take a crack at another of my HV units.

No stable HV, B+ is shifting around.

I traced back to Q900 (BU409) and found it to have bad voltages (+ / - 26V
on all three legs). Figured it was shorted so replaced it with a known
good.

Turned the monitor on and got HV crackle, YAY I thought. Then I heard snap
and smelled the magic smoke. BOO.

BU409 now giving the same values as before.

I have recapped the HV and replaced Q901, 902.

Anyone have a reasonable source for BU409's? And any ideas of what is
blowing them?

And while I am at it, source for the 150V 1w zeners?

Thanks,

David

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Received on Mon Oct 10 01:50:28 2011