91L98Z28

I recently fired up my PP2 for the first time in several months, and it seems to be dead. It will read just fine, but will not program. The "00000" counter which normally would go up as it programs the chip stays at "00000", eventually increments to "00100" and then either zillions of "expected - found" rows pop up in the right side of teh screen or a message that the device did not program.

has anyone successfully repaired one of these guys and/or have any input on what to test/check ?

I'm using AT29C256 exclusively.

91L98Z28

using the test mode build into the intronics software, my Vpp(12) measures 16.4v, Vpp(12.5) measures 16.4v, Vpp(25) measures 24.9v, and Vpp(21) Measures 21.0v.

the AT29C256 is a Vpp(5) but there is no test mode for 5v.

While attempting to program the chip, pin 1 only gets up to about 4.3v. is that high enough?

hmm.

dimented24x7

iTrader: (2)

Definatly sounds like its flakey. I had one go out on me. A switching transister caught fire and did a number on the board. Despite that, it still works fine with a replacement.

Have you tried contacting Carl at xtronics?

91L98Z28

well, I talked to the PP2 folks. They suggested that perhaps a transistor on the bottom of the board (a 2N2222) had failed. swapped it with no effect.

So, I replaced the PP2 with a ChipMax 2, a USB programmer from EE Tools. Pricy but built like a tank, it will probably last forever. works great!