Vivitar 2000 (31657 board troubleshooting), Basic tests of inverter components (transistor, transformer, diodes) Options

[dkirk]

Here are some basic trouble shooting steps to help try and locate failed components on the 31657 board found within some versions of the Vivitar 2000 Slave Flash. The only equipment required is a multimeter capable of measuring resistance and checking diodes.

The steps below are an attempt at performing basic in circuit (but energy disabled) tests of the 3 main inverter components that may fail.

In Circuit Components To Be Tested
Inverter Transistor
Inverter Transformer
Inverter Diodes

 Vivitar_31657_Board_Troubleshooting.jpg ( 113.97K ) Number of downloads: 76


Inverter Transistor (2SC3420) test with meter in diode check mode.
1) Black Lead on 1 and Red Lead on 3 : Reading should be a low value (indicating conduction)
2) Black Lead on 2 and Red Lead on 3 : Reading should be a low value (indicating conduction)
3) Red Lead on 1 and Black Lead on 3 : Reading should be a high value (infinite)
4) Red Lead on 2 and Black Lead on 3 : Reading should be a high value (infinite)
5) Red Lead on 1 and Black Lead on 2 : Reading should be a high value (infinite)

Inverter Transformer test with meter in resistance mode.
1) Resistance measured between 4 and 5 should measure approximately 0 ohms
2) Resistance measured between 6 and 7 should measure approximately 140 ohms
3) Resistance measured between 7 and 8 should measure approximately 140 ohms
4) Resistance measured between 6 and 8 should measure approximately 0 ohms

Inverter Diode #1 test with meter in diode check mode.
1) Red Lead on 9 and Black Lead on 10 : Reading should be a low value (indicating conduction)
2) Black Lead on 9 and Red Lead on 10 : Reading should be a high value (infinite)

Inverter Diode #2 test with meter in diode check mode.
1) Red Lead on 11 and Black Lead on 12 : Reading should be a low value (indicating conduction)
2) Black Lead on 11 and Red Lead on 12 : Reading should be a high value (infinite)

Working on your flash unit is done at your own risk to both you and your equipment. Make sure you discharge all energy (capacitors, etc.) before working on the flash unit, and disable all energy sources such as the battery.

Good Luck,
Don

[CaptNasty]

Great work, as usual, Don!

[bhuska]

Fantastic work Don! I'd be lost without your help!

[Hill Hopper]

I used a number of these modified using Jons mods back several years ago and never had one fail. Has there been problems recently? What were they being controlled with?

[dkirk]

Hello Butch,

Bhuska was playing with one that was being controlled by Brians 5uA day/night circuit and when he was carrying his stuff back upstairs as one big rats nest he got shocked and since then his Vivitar 2000 is dead so he asked for some troubleshooting instructions.

Don

This post has been edited by dkirk: Apr 10 2007, 03:06 PM

[treetop]

I must be lucky Never been shocked or do i have a parts drawer of dead flashes Good work Don Thanks

[bhuska]

Don, I Just finished the test on my non-working 31657 board...took all of 5 minutes to do!

My results: steps 3, 4, and 5 for the Inverter Transistor failed. They measured .001, .027, and .027 respectively. Should simply removing that transistor and replacing it with another of the same part number fix the slave board?

On another note...Is .583 considered a low value in diode check mode? Compared to the values for other components of .001 and .027 it is relatively high. I measured .576 for step 1 for Inverter Diode #1 test, and .583 for step one on Inverter Diode #2. Are these numbers acceptable? Thanks again for your help and the time you put into this.

[dkirk]

Bhuska,

Yep, sounds like the Inverter Transistor has indeed failed. The cross reference replacement transistor for the 2SC3420 is NTE2513 and you can buy this from Mouser for $1.18. The Mouser in house part number is 526-NTE2513.

I don't have any 2SC3420 (or NTE2513) transistors. I have some 2SC2500 transistors which are used on the DF500 board version of the Viv 2000 but they have a much lower current rating and therefore I suggest you go with the 2SC3420 equivalent transistor.

The diode values that you measured are reasonable.

Great job measuring your board, and keep me posted on your repair work.

Don

Don, I Just finished the test on my non-working 31657 board...took all of 5 minutes to do!

My results: steps 3, 4, and 5 for the Inverter Transistor failed. They measured .001, .027, and .027 respectively. Should simply removing that transistor and replacing it with another of the same part number fix the slave board?

On another note...Is .583 considered a low value in diode check mode? Compared to the values for other components of .001 and .027 it is relatively high. I measured .576 for step 1 for Inverter Diode #1 test, and .583 for step one on Inverter Diode #2. Are these numbers acceptable? Thanks again for your help and the time you put into this.

[bhuska]

IT'S ALIVE!!!!!!!!!!!!

Thanks for the help Don! Swapped the transistor and the flash works great!

I haven't hooked it back up to the day/night circuit yet, but I may play around with the resistance values. Before my slave died, I had it hooked up to 200K (two 100K in series) and carried the circuit to a darker room and it seemed to turn on at an appropriate light level (or lack there of). More testing will tell. Keep us updated with what you find when you get the MAX391's in. Thanks again!

[dkirk]

Bhuska,

Great repair job. It should now work ok as long as you don't let the smoke out again.

I just posted my mods to Brians 5uA day/night circuit which I think will help you out.

Don

[jschu121]

Thanks for your work, dkirk. I can hear the capacitor charge up, but it doesn't seem to stop charging. Using the hot shoe trigger wires I can't make the camera flash either. When I go through the testing procedure it appears the inverter transistor is bad. It's only the one measurement (4) that is bad. Could this be causing the other problems? I included the other information in case anyone had or has a similar problem. Should replacing the inverter do the trick, or are there other problems? Thanks for your help


1) Black Lead on 1 and Red Lead on 3 : .55
2) Black Lead on 2 and Red Lead on 3 : .55
3) Red Lead on 1 and Black Lead on 3 : infinite
4) Red Lead on 2 and Black Lead on 3 : .78 (bad)
5) Red Lead on 1 and Black Lead on 2 : infinite

Jeff

[dkirk]

Jeff,

If the inverter transistor is bad, then the capacitor will not charge. You say you hear it charging, but this does not make sense if the inverter transistor is indeed bad.

Therefore lets check and see if the capacitor is really charging. Apply power to the slave flash for about 15 seconds, and then measure the voltage across the large slave flash cap. Your meter should be in DC volts mode, and the range should be at least 350 volts. Be careful when doing this measurement, and let us know what you measure.

Note : your inverter transistor does indeed look bad based on your number 4 measurement, but lets make sure by doing the above test.

Don

This post has been edited by dkirk: Jul 26 2008, 12:39 PM

[jschu121]

Don,

I did as you said and the voltage across the capacitor is 350 volts. The high pitch noise exists whenever I power it on. I mentioned that I couldn't jump the peanut wires to make it flash manually, but it also doesn't work with the peanut. (I tried it manually to see if the peanut was bad). I notice that the green bulb looks to be blown. There is no continuity across the leads. Not sure what's going on, but I thought I'd give you as much information as possible. Thanks for your help.

Jeff

[dkirk]

Jeff,

OK, if the capacitor measures 350 volts, then the inverter is working just fine. With the slave flash charged up, measure the voltage across the flash tube and tell me what you measure. It should measure the same as the voltage you measure across the slave flash cap.

Note : did this flash recently stop working, or are you just putting this unit into service? What mods have you done, and has it worked since you did the mods?

Don

This post has been edited by dkirk: Jul 26 2008, 01:10 PM

[jschu121]

Don,

The voltage across the flash bulb is the same as that across the cap. I had it working this morning. I went back to solder everything up. I guess the cap wasn't fully discharged and it sparked a little. There also looks like a small dark spot in the lower left corner (as shown in your picture). Sorry for the trouble.

Jeff