Malfunctioning Willem EPROM programmer. (SOLVED)

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Malfunctioning Willem EPROM programmer. (SOLVED)
by on (#125797)
I recently bought a cheap Willem on eBay to play around with making some reproduction carts for myself and a friend but it seems the programmer is defective (or so I think) and it is too late to return it.

The issue I am having is that if fails to write to EPROMs on the same location every time on the same type of chip. I took a multimeter to it and found that I am getting 5.42v on pin 22 of the 32 pin ZIF socket where I am expecting 6v and 4.46v at pin 26 where, again, I am expecting 6.0v. All other pins measure 6.0v and Vpp and Vcc measure good.

Are there any Willem experts on here that might be able to help?

P.S. I am trying to write to a 27c010 and I do have a 12v 500mA power supply powering the board. The measurements were taken with the H/W Test tab enabling all pins.
Re: Malfunctioning Willem EPROM programmer.
by on (#125942)
I don't know why people keep buying Willem.

I can't fix the issue because Willem designs are just so flaky it could almost literally be ANYTHING.

I would recommend, if you decide to buy a new programmer, get a MiniPro TL866CS or TL866A. Those will do pretty much everything NES, and be about the same price as a Willem.
Re: Malfunctioning Willem EPROM programmer.
by on (#125949)
I was considering one of those but I could not find any 42 pin dip adapters for programming larger EPROMs such as the 27c322 for the Sega Genesis or SNES. The other options left would have been the Willem or the GQ-4X, and the Willem was a third of the price with the needed adapter. I guess my frugality bit me in the ass.
Re: Malfunctioning Willem EPROM programmer.
by on (#125955)
Dunno bout SNES as I've never done any SNES stuff.

But I own a TOP3000, it's a 48-pin device and does 27c322 without issue.

Software's a bit crap but once you get used to it it's fine.
Re: Malfunctioning Willem EPROM programmer.
by on (#125977)
I can only tell you what my experience has been with a Willem.
I have burned EPROMs from 2732-27C010, for the most part without too many issues. I use USB to power it and that seem fine even with EPROMs.
I've needed to re-position the chip in the ZIF to get a good connection a few times, but could have been dirty pins on the pulls I have. A few chips just have bad cells; no matter how long under the UV the cell won't erase.
The hardest part it getting the board setup correctly; the jumper settings are a little cryptic. The DIP switches act a little flaky so I take extra care there, making sure I get a good 'click'.
So to sum up, Yea the Willem is a PITA sometimes and avoid it if you want to have a production burner but for occasional use it's been OK. For my wish list, I would like to find a burner that can handle GALs as well as EPROM/EEPROM/Flash. at a 'hobbiest' price.
Re: Malfunctioning Willem EPROM programmer. (SOLVED)
by on (#126398)
Turns out the Parallel Port on the laptop I was using to connect the programmer to was not compatible enough. All the "issues" I was having were also non-issues.

The low voltages were all "good enough" as the EPROM's datasheet showed that trigger voltages needed to be at a MINIMUM of 2 volts so even the low voltage of 4.46 was more than enough. It is sloppy engineering, but close enough.

If anyone else is having this problem I am now able to program an EPROM chip with out issues. The board I have is labeled "2010 PCB 50" and I am using Willem software version 0.98D12 without any suffixes such as C2 or C3 etc. and the two board version/compatibility jumpers on the left side of the board are jumping the right most pins.
Re: Malfunctioning Willem EPROM programmer. (SOLVED)
by on (#126418)
Good to hear, glad you got it worked out. They DO cut corners with Laptops, run into the same sort of issues with the USB :)