TECH: data east star wars (no +68 volt from power supply) dmd is dead

[gangstarr]

display is dead (but is a known good working display). all voltages to
display from power supply are fine except the +68 is not there) its
pretty much at ZERO.

it has a new connector at power supply, still no +68vdc.
power supply pins have been reflowed and most caps replaced, a couple
i didnt have (150uf and another odd uf).

what else? thx

[firepower]

+68v circuit is composed of:
MJE15030 transistor Q3 (Q1 on WPC95)
MPSD02 transistors Q2 / Q10 (Q2 / Q3 on WPC95)
1N4759 zener diode D3 (D2 on WPC95)

Start by replacing the 1N4759 62 volt zener diode. Then work through
the transistors replacing Q3, Q2 and Q10.

The DMD display card should be the same on your DE, anyway I fixed my TZ
that way. If it is the same ciecuit, this may help:
http://www.firepower.2ya.com/tz/wpc-dmd-hv-all.pdf

If I'm mistaken, I'm sure someone else will chime in and correct me.

-Richard

Post by gangstarr
display is dead (but is a known good working display). all voltages to
display from power supply are fine except the +68 is not there) its
pretty much at ZERO.
it has a new connector at power supply, still no +68vdc.
power supply pins have been reflowed and most caps replaced, a couple
i didnt have (150uf and another odd uf).
what else? thx

[firepower]

Scratch my previous reply if you see it. I'm assuming you know it's not
fuses and you have a voltage coming in and measurable on the banded side
of D5 with respect to GND. If no voltage there, suspect fuses or
replace D5 with a (normal) diode 1N4004. That would be an easy fix.

Be careful not to touch anything when working on HV. Been there, done
that. Once.

Circuit for +68 voltage is components under CN6 of the Power Board (PSU)
+68v circuit is composed of:
MJE340 transistor TR3
MPSA92 transistor TR1
1N4760b 68v zener diode D9
1N5228 3.9v zener diode D6
1N4004 (normal) diode at D5.

Check values of resistors R15, R12, R8, and especially R11 against
schematics in manual. Any out of spec need to be replaced first.
Then replace the 1N4760 68v and 1N5228 3.9v zener diodes and test DMD
again.
Then work through the transistors, replacing TR1 then TR3.
Looks like you have caps covered, but C10 is important if you haven't
replaced it.

Anyways, I fixed my TZ DMD that way and the DMD display psu should be
similar on your DE.

I'll post this info on the PinWiki Repair site, so someone that is more
familiar with DE repairs can correct anything wrong here.

Cheers and best wishes,
-Richard

Post by gangstarr
display is dead (but is a known good working display). all voltages to
display from power supply are fine except the +68 is not there) its
pretty much at ZERO.
it has a new connector at power supply, still no +68vdc.
power supply pins have been reflowed and most caps replaced, a couple
i didnt have (150uf and another odd uf).
what else? thx

[gangstarr]

can i use a mje15031 instead of the mje340?
reason i ask, i have all the parts above in my stash except that. if
not, what other boards may have this mje340 that i can rob that part
from?
or, is there another cross?

[firepower]

No, that's not going to work. The 15031 is a PNP, while the mje340 is
NPN - different animal not even close.

Try this datasheet for a cross NTE157 springs to mind, as does 2n6557
http://noel.feld.cvut.cz/hw/st/3649.pdf

Hope this helps. -Richard

Post by gangstarr
can i use a mje15031 instead of the mje340?
reason i ask, i have all the parts above in my stash except that. if
not, what other boards may have this mje340 that i can rob that part
from?
or, is there another cross?

[gangstarr]

helps alot
im hoping i have a board here from something else i can rob it from,
any idea what other boards have this? i have all of the other parts
here.

[GPE]

The NTE157 is the same as an MJE350 with the TO-126 package..
Electrically - the 2N6557 is similar to the MJE350 -but- the 2N6557 was a
TO-202 package. These are the same as the
SDS-whateveritwas part number that was used on the Williams alpha numeric HV
supply and are made of unobtanium -- goofy pinout that required swapped
legs.

The MJE15030 is a heavy duty version of the MJE340
and
The MJE15031 is a heavy duty version of the MJE350

-- Ed

Post by firepower
No, that's not going to work. The 15031 is a PNP, while the mje340 is
NPN - different animal not even close.
Try this datasheet for a cross NTE157 springs to mind, as does 2n6557
http://noel.feld.cvut.cz/hw/st/3649.pdf
Hope this helps. -Richard

Post by gangstarr
can i use a mje15031 instead of the mje340?
reason i ask, i have all the parts above in my stash except that. if
not, what other boards may have this mje340 that i can rob that part
from?
or, is there another cross?

[firepower]

Thanks Ed. Looks like I gave incomplete information. It was late for
me (4am) when I posted. You sir are a wealth of knowledge and keep us
Techs honest on the electronics.

I'll try to 'make good' here so the post useful on a later search:

Yeah, the SDS20x are NLA (no longer available). You need both of those
for +/-100v diplay HV on Williams Sys3-7 PSUs. And other Display PSUs.

SDS201 - NLA. Use MJE15030 note: part has different pinouts.†
SDS202 - NLA. Use MJE15031 note: part has different pinouts.†
†The goofy legs crosses over legs and looks like this:
Loading Image...

Sorry I can't post pinrepair links, but this appears to be a great
description of the problem. Thanks to Ray Johnson at Action Pinball for
explanation of the two methods of using this X-istor:
http://www.actionpinball.com/tech/wmshv.htm

Cheers

-Richard

P.S. Good Luck to gangstarr on fixing the HV to your Display.

Post by GPE
The NTE157 is the same as an MJE350 with the TO-126 package..
Electrically - the 2N6557 is similar to the MJE350 -but- the 2N6557 was a
TO-202 package. These are the same as the
SDS-whateveritwas part number that was used on the Williams alpha numeric HV
supply and are made of unobtanium -- goofy pinout that required swapped
legs.
The MJE15030 is a heavy duty version of the MJE340
and
The MJE15031 is a heavy duty version of the MJE350
-- Ed

Post by firepower
No, that's not going to work. The 15031 is a PNP, while the mje340 is
NPN - different animal not even close.
Try this datasheet for a cross NTE157 springs to mind, as does 2n6557
http://noel.feld.cvut.cz/hw/st/3649.pdf
Hope this helps. -Richard

Post by gangstarr
can i use a mje15031 instead of the mje340?
reason i ask, i have all the parts above in my stash except that. if
not, what other boards may have this mje340 that i can rob that part
from?
or, is there another cross?

[firepower]

I have also updated and corrected the PinWiki.com page to reflact these
changes. It now covers the +68v and -100 /-93v circuits and parts list.
http://pinwiki.com/wiki/index.php?title=Data_East/Sega#High_Voltage_Missing_at_the_DMD_display

[gangstarr]

THX so much
I Was able to purchase the correct mje today.
ill work on it soon and post results.
this games a keeper and me and my son are working on it together...
got to get the kids learning early on this stuff:).

[firepower]

No probs. Please do post back your results to this thread. If you have
comments or amendments I will update the PinWiki site in order to help
others.

-Richard

Post by gangstarr
THX so much
I Was able to purchase the correct mje today.
ill work on it soon and post results.
this games a keeper and me and my son are working on it together...
got to get the kids learning early on this stuff:).

[gangstarr]

installed it and still not working. also installed other parts as
noted.
tested/repaired the traces to that compnenent as well as they were
burnt some.
im getting 20 volts dc now , (still not 68 vdc)
it was at zero volts before thow...

[KenH]

Post by GPE
supply and are made of unobtanium -- goofy pinout that required swapped
legs.

I prefer standing them up vertically to twisting the leg. I never see
that as an alternate installation method.