Sound buzz (noise) on D.E

[MartyJ]

Hi guys,

A question to throw over to the experts...My D.E Simpsons has it slightly and moreso with the LAH is buzzing / noise from the speakers.  It is most noticable when in attract mode, and you seem to get the G.I interference when they flash on and off.

I've done some research which suggests firstly - make sure boards are screwed in tightly (this is done).

Secondly - there is some information about replacing the caps on the sound board.  This I have not done, as I am unsure what caps they are referring to and what values need to be replaced etc..

Thirdly on the rec.games.pinball I found a suggestion about a stern service bulletin which refers to buzzing at low sound volume...  This I am unsure of and don't even know if they are the same boards.

http://www.sternpinball.com/downloads/sb133.pdf

I would not say the noise is unbearable and I am aware it is a feature of D.E pins but any advise would be appreciated!   

[Strangeways]

Great info here Marty,

http://www.pinrepair.com/de/index3.htm#sound

Check your ground straps to the display board. Clay's doco also explains the revision of the boards.

[MartyJ]

Great info here Marty,

http://www.pinrepair.com/de/index3.htm#sound

Check your ground straps to the display board. Clay's doco also explains the revision of the boards.

Thanks Nino,

I've re-checked the grounding straps, from the backboard (tightened up the one which goes onto the locking mech, but others all good.  Checked its path back to where it hits the transformer and all in tact.

According to Clay's site it states the sound board should be 520-5050-03.  The sticker (little white one) on mine reads 520-5050-02.  Clays states the boards are not upwards/downwards compatible then further reading (google) suggests it can be changed with jumpers? I am a little confused with the jumpers as to what I should have.  As far as I know I am getting sounds / music that I should be.
 So if this sound board is OK to be used (nil probs except for hum / G.I noise) I will look at changing the cap.

His site states:
Also it could mean the large filter capacitor (usually 1000 mfd at 16 volts) on the sound board needs to be replaced. Look for a large capacitor that connects +5 volts to ground.

This is the second part.  Not having the schematics I don't know which is the 'larger capacitor that connects +5 volts to ground' on the actual sound board.  From a visual inspection there is a larger capacitor on there (well bigger than others).  Third question what replacement do I purchase - ie 1000 mfd filter capacitor or is a greater one required?

Thanks again

[Retropin]

The capacitor you should be looking for will read on it 1000uf 16V.

The voltage is not so important, it could be 16V, 20V etc, It will definately NOT be under 16v.

replacement should read same capacitance value - 1000uf but voltage rating can be 16v or higher

[MartyJ]

The capacitor you should be looking for will read on it 1000uf 16V.

The voltage is not so important, it could be 16V, 20V etc, It will definately NOT be under 16v.

replacement should read same capacitance value - 1000uf but voltage rating can be 16v or higher

Last noob question (for tonight) is 1000mdf the same as 1000uf?

ie.
http://www.jaycar.com.au/productView.asp?ID=RE6316&CATID=51&keywords=&SPECIAL=&form=CAT&ProdCodeOnly=&Keyword1=&Keyword2=&pageNumber=&priceMin=&priceMax=&SUBCATID=859

[ajlaird]

The capacitor you should be looking for will read on it 1000uf 16V.

The voltage is not so important, it could be 16V, 20V etc, It will definately NOT be under 16v.

replacement should read same capacitance value - 1000uf but voltage rating can be 16v or higher

Last noob question (for tonight) is 1000mdf the same as 1000uf?

ie.
http://www.jaycar.com.au/productView.asp?ID=RE6316&CATID=51&keywords=&SPECIAL=&form=CAT&ProdCodeOnly=&Keyword1=&Keyword2=&pageNumber=&priceMin=&priceMax=&SUBCATID=859

Yep, mfd = uf or more correctly uF

[Strangeways]

Marty - download a manual of a game around the same period - then you can check the CPU / PSU schematics etc...

[Retropin]

uF ??? - LOL

[ajlaird]

uF ??? - LOL

Well, don't know enough to put the micro symbol in, but a lot of people use u instead of micro including Jaycar

[MartyJ]

Marty - download a manual of a game around the same period - then you can check the CPU / PSU schematics etc...

Hi Nino,

I've d/l the D.E LAH manual from IPDB but nil schematic...I found what I was looking for with Pinball-Fixers for sound board!!!

I've pulled the board out and obs that all the caps were 25v not 16v.  I've swapped out the one which I believe was correct (C30) and put new cap in.  Nil value.  Still the same with G.I interference so I guess what I've got is as good as it will get....

Next time I'm down at Marks I'll have a listen to his NIB LAH and compare & I'll try my hardest not to buy another machine!

[markc]

& I'll try my hardest not to buy another machine!
[/quote]

not if i have anything to say about it 

mate you are more than welcome to come in   
its still the best ever LAH  I have seen

[pinnies4me]

I've got some DE schematics I can email over if useful (maybe to keep for next time anyway). Shoot me your email addy and I'll send over.

[MartyJ]

OK, in between working on the PF, I have played a few games on my LAH today....The humming on the sound is starting to get to me..

At this stage I've only replaced the one cap on the sound board (as per Clay's guide)...All backbox pcb screws are present and tight (even bought some new ones from Mark)...The two connectors which attach the screen display / speaker panel are on and tight to the metal tabs.

My question is  - will replacing the -12v caps on the power supply have any assistance?  Or should I look elsewhere?

Thanks guys

[Nug]

to a certain point all DE games do this...its mesmerising in attract mode

AG&C games also buzz a bit with lamp shows..turn it up

[MartyJ]

to a certain point all DE games do this...its mesmerising in attract mode

AG&C games also buzz a bit with lamp shows..turn it up

Hmm, I've read that too!  But my D.E Simpsons has a little, but only about 25% of what LAH has.  I get the G.I interference as well...