| T O P I C R E V I E W |
| jroesner |
Posted - 08/08/2007 : 12:38:18
I have 20 2716 chips that I am failing to program..
-Dual Power Willems, using external 12V ac adapter
-2716 Eprom (Intel)
- Dip Switches - configured per 0.97ja
- tWP 25.0ms
- tWC 50.0us
Jumpers: JP5 - Down, JP6 - Up (25Volts)
I constantly get errors while programming. Any help greatly appreciated.
I put the chips back under the lamp to nukem and try them again.
Thanks
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| 1 L A T E S T R E P L I E S (Newest First) |
| DL |
Posted - 08/09/2007 : 12:08:23
Hi,
For starters, an unmodified Willem programmer (except the 4.1 with optional relay) will have voltage drop problems with NMOS EPROMs.
Enter the Test H/W tab. Set programmer for 2716. Insert device in socket, enable VCC, and measure voltage at pin 28 on the socket. If you don't measure at least 4.5V, you can't even read the device reliably.
You want to program with VCC=5V (at the device) and a 50mS programming pulse.
You could have a problem with VPP. With no device in the socket, enable VPP and measure at pin 25 on the ZIF socket. If you have 25 +/-1V, try loading VPP with an 820 ohm 1W resistor; the regulator might be having problems with supplying the current needed to program. Measure the voltage immediately after enabling VPP and then 30 seconds later. VPP should not drop below 24V.
HTH,
Dennis |
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