Shop Gear Repairs

[channelmaniac]

Model: Data I/O Model 22 EPROM Programmer
Symptom: Fails self test: ROM ERROR

This was a strange one. Pulled the EPROMs from the unit and read them in on another programmer. Sent the checksums off to the 'official' repair person for the unit. They were good. Burned a new set of ROMs and found 1 that would read but would not work properly at normal operating speed. Replaced that EPROM to fix the programmer.

[channelmaniac]

Model: Data I/O Model 22 EPROM Programmer
Symptom: Will not read or program ICs correctly

When troubleshooting this programmer it's important to note what modules are in it. In this case the 351A-064 PROM module was installed. Removed the module and the programmer worked as it should.

Disassembled the module and found that pins 13 and 14 on the left socket were shorted together. The solder on the socket wasn't factory. Pulled the socket and removed a solder bridge from the top of the board. Reassembled and tested the programmer successfully with the module installed.

[channelmaniac]

Model: Data I/O Model 22 EPROM Programmer
Issue: Software needed to run optional module

This model of programmer has its software in EPROMs installed on the bottom board. If an optional module is installed the software on ROM must be updated. According to the authorized support person this software is custom for each module. I ended up purchasing a Model 22 and wanted the optional PROM programming adapter, 351A-064, and could not simply acquire one apart from the programmer because of this.

Make sure to get the programmer WITH the adapter installed! Do not buy them separate unless you can verify the correct software is installed. To my knowledge this is not possible to verify from the chip labels or from the front panel.

[channelmaniac]

Model: Data I/O Model 22 EPROM Programmer
Issue: How do you get larger amounts of data on it to program an IC?

This is an OLD programmer and it has an archaic RS-232 interface. This interface is well suited to hook into development tools but not really for a PC. If you have a small PROM chip to program it's a simple task to manually key the data in but... that's not the case for a 2708 (1k x 8 EPROM). There you will need to enter up to 1024 values to program into the chip.

To get around this simply program the code on the smallest EPROM your newer programmer can handle. This will most likely be a 2716 EPROM. Insert that chip into the old programmer, read it into RAM, then program it on the needed chip.

[Ken Layton]

If you have a Simpson 260 volt-ohmmeter regardless of vintage, here is all about them:

http://www.simpson260.com/

[channelmaniac]

Model: Andromeda Labs AR-32A EPROM Programmer
Symptom: Will not program ICs

An AR-32A programmer stopped programming ICs. Tested the bank of 8 DIP switches and found that switches 4 through 8 were stuck open. Replaced the DIP switches and tested. The device to be programmed had 8.3 volts on the programming voltage pin that dropped down to 4.3 volts when reading or programming. Replaced a shorted 2N3906 transistor and tested by programming some EPROMs.

[channelmaniac]

Model: Fluke 9010A Micro System Troubleshooter
Symptom: Upgrade Firmware

Unit was running revision 2C firmware. Replaced U9, U19, and U21 with 27C128 EPROMs programmed with version 3A firmware. Tested unit.

[channelmaniac]

Model: Fluke 9000-Z80 (Fluke Z80 Pod)
Symptom: Fails self test: Code 00

Ribbon cable was physically damaged. Built a replacement ribbon cable and tested.

NOTE: There are 2 ways to rebuild this cable. The first is to use the same type of braided ribbon cables. This pod had 2 of those 40 pin braided ribbon cables - one for odd and one for even pins. The odd pins on one of the ribbon cables were connected to ground. The second way is to use shielded ribbon cable and ground the shield.

After building one with 2 40-pin ribbon cables I would highly recommend using a single shielded ribbon cable.

[channelmaniac]

Model: Philips LCDT 19PFL5422D/27B
Symptoms: Loses audio and picture. Shuts off by itself

TV would work for a couple of minutes then lose audio. About 10 minutes later it would lose video. It progressively got worse until it would only power up for a few seconds then go off/on several times by itself before shutting off.

Replaced three bad capacitors on the logic board and tested.

[channelmaniac]

Model: TOP853 Universal Programmer
Symptom: Would not program EPROMs

Programmer would create the proper voltage levels but they would drop off quickly during programming. Replaced bad MC34063 voltage converter IC and tested.

This unit uses surface mount 4049 ICs floating above ground and powered by the Vpp voltage levels. These must be checked for failure when replacing the MC34063.

[channelmaniac]

Model: BK Precision 1479B Oscilloscope
Symptoms: Input mode switches not working properly on Channel A or Channel B

Scope worked, but the input mode switches (AC - Gnd - DC) had to be jiggled to get them to work in the desired mode.

Cleaned the input mode switches and the Volts/CM adjustment pots. Resoldered all the Molex style board interconnects to fix cracked solder joints. Repaired another 11 cracked solder joints. Tested.

[channelmaniac]

Model: DT-1 Dynamic RAM Tester
Symptom: Dead

Replaced broken on/off switch, backed up program ROM, and tested.

[channelmaniac]

Model: HP 10529A Logic Comparator
Symptom: Chips in universal socket adapter get hot

When using the 10529-60017 (Series 2204) universal socket, 74LS157 chips get roasting hot. LED 11 flickers on known good chips. Replaced 2 shorted Germanium diodes and tested.

1N270 diodes were successfully used as replacements for the HP diodes, part number 1910-0047.

[channelmaniac]

Model: Xeltek Superpro/L+
Symptom: Dead

Power supply had no output. Opened the supply, replaced a 1uf/50v and a 47uf/25v in the high voltage section, and resoldered several cracked solder joints. Tested.

This power supply was sealed. To open such a power supply, simply use a small ball peen or brass hammer to crack the glued joints apart. Repair the power supply and reseal it with epoxy or super glue.

[channelmaniac]

Model: Pace SX-70 Desoldering Iron
Symptom: No suction

Iron was purchased as parts.

Replaced bad front seal, cleaned heater bore, and installed a new tip. Replaced broken glass chamber, reinstalled S baffle, and installed a new filter. Tested.

[channelmaniac]

Model: Anatek Corp Blue ESR Meter
Symptom: Will not read caps

Looked at a kit a friend built. Unit would read the test resistors but all caps read as .00 ohms. Found a 2N2904 and 2N2906 transistor that were swapped during the kit build. Swapped the transistors and tested caps successfully.

[channelmaniac]

Model: HP 1703A Oscilloscope
Symptom: No trace

Cleaned pins on 2 74L00 ICs, Fixed a bent pin on an IC that was folded under the IC. Tested.

[channelmaniac]

Model: Data I/O Series 22
Symptom: Dead. Nothing on display.

The voltage to the main board was 4.6v. Removed reseated the cable from the power board a few times, it read 4.98v on the main board, and was booting to a SYSTEM ROM ERR message. Replaced the old EPROMs with ones burned with newer code and it booted and passed self tests.

It has the following options in ROM: 30, 31, 32, 40, 43, 46, 48, 49, 50, 53, 55, 57, 60, 63, 66, 69, 72, and 74.