Peavey DPM 2 / 3 / 4 / SI ~ guide to UPGRADE EPROMs

I have compiled some frequently asked questions relating to updating the repair and software EPROMs in your Peavey DPM synthesizers, for those of you who don't know Peavey once made synthesizers, maybe you should consider buying one used, and sell your old Korg Wavestation. To me the cool and fat sounds are better than the D-50, D-70 can offer even. CHECK EM OUT! ; )

What DPM EPROMS ARE AVAILABLE CURRENTLY?

I provide (here on ebay) update chips for Following Peavey DPM Synthesizer Keyboards and Rack mount synth models:

DPM3 (The first generation, 16 Polyphonic, 61 keys, 9 track seq)
DPM 3 SE (added sample editing)
DPM 3 SE Plus (expanded sequencer memory)
DPM 4 (32 polyphonic)
DPM 488 - (88 full weighted keys!)
DPM 2 (49 Keys)
DPM 2 SI enhanced version on the DPM2
DPM SI (76 Keys! 16 track seq)
DPM SP (Rack mount unit)        
DPM SP plus (Rack mount unit)
(DPM V2, V3, and C8 - coming soon)


WHY GET NEW CHIPS?

Have them on Hand - Get them now while they are available, save them for when you need them.
Update your software with a newer version - Lesser known bug fixes, enhancements,
and over all stability and performance issue. Often accompany the revision of the software.
I sell only the final versions of the software for the DPM series. So rest assured you
only gettng the latest and last *Final* versions.


Do ROM chips defective with age?

True it is more notable for ROM, no EPROM chips to get what is called "Bit rot".
When age EPROMs might need to be erased and reprogrammed,


METAL OXIDIZATION ON PINS?

It may look silver, but a light layer of oxidized metal is all you need to affect the electrical connection
in the socket. 5v with a lower current won't take much resistance to lower the effective levels of voltage/current  in the circuit.
Directly affecting performance, stability and even "booting up".
A simple thing to try involves first that you pull the chips.
 (Warning watch how it is seated, inserting it backwards, will damage the chip!)
Take a clean pencil eraser and clean the IC pins. Reinsert the chips in the proper orientation/position.
Acid damage from a corroded battery can have damage you can see.
But this is one thing to try.


BATTERY CORROSION AFFECTING SOFTWARE ROMS?

Battery corrosion doesn't usually affect the area in the DPM 3 & 4 keyboards circuit boards.
But in Dpm 2 DPM 2 SI keyboards, the battery is near the ROM chips, and the unseen damage could be where the chips
are seated. This includes the sockets. For the price of pull, erase and reprogramming, in the least with the
new ROM chips, you can rest assured knowing they have been tested. SO that all would remain is perhaps remain a
cleaning or replacement of the socket.
Something any good technician can do.


What is it meant by a "CRC Check and verification"?

This is a process only accomplished with the ROM chips removed and in a EPROM reader/writer.
The Software on the chip is compared with an "Image" to check for corruption.
Passing "Verification" means it is a perfect uncorrupted copy, bit by bit perfect. "No errors"
Check sa re tested AND verified before shipping.


I TOOK OFF the CHIP LABELS..AND...

No No! Don't do this! Even if the inside of the case is sealed from ultraviolet light that might
seep in. UV rays from the sun CAN erase corrupt the programmed software. Don't remove the labels -=PERIOD=-.


NOTES ON THE PLACEMENT OF THE CHIPS:

Yes, and only replace the "HI" eprom chip with it's "HI" replacement.
NOTCHES NOT LABELS - Sometimes the labels don't tell you how to place the chips on the board. You might have
an "upside down" label and put the chip in backwards! Only go by the "notch" in the chip when replacing the chips for
a proper orientation/positioning.

BE CAREFUL, when pressing in the chips, so you don't apply so much pressure on the board, which could crack the board,
losen solder joints. Etc. Then you will have more trouble than you began with. This is one of many reasons why we recommend a technician to QUALIFIED service technician to install the chips.

DOES PEAVEY STILL SERVICE THESE?

Yes. Not sure for how long though. Most often as these units are quite heavy, it is better to remove the suspected board from the unit yourself, and send it in. Most often this will be the main board with the DSP chips on board. Mainly because this board holds the old PC mounted backup battery that likes to go bad and leak. F'ing up your board. You can bet if your ROMs are OK, this is more likely an issue than the MEMORY. But there are no guarantees...
Send this board to peavey service, but call them first to let them know it is coming...

ARE SCHEMATICS AVAILABLE?

Most, if not ALL are NOW only available from my store here on ebay.
Peavey parts only carries about 2-3 I think. Example DPM 4 / 488 is not available...
You can only get them through my store as far as I know...




-Kenneth Deel
(store:) Otherworlds Unlimited