CA90 TR firing problem

[Sep II]

UPDATE: Problem solved! Originally, the CA90 TR wouldn't fire when it was hooked up to a 8.4v battery. The problem was that the 8.4v wasn't strong enough to power the internals - however, once a 9.6v mini-type battery was installed, the CA90 TR fired with no issues at all! It simply needed a higher voltage battery.

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Hello all!

I've been lurking here for a while and I must say these forums are simply a wealth of information - thank you very much to everyone for your analysis and opinions! They have proven invaluable

Anyways, onto the problem... it's too bad my first post has to be about a possible lemon I recently received (TL;DR: I plugged in a stick-type battery into the p90 to test the gun, it fired once (almost), then refused to do anything thereafter (of course this happened on Friday the 13th).

Of course I'll post this up here in the noob tank - I really hope I'm just being an idiot and I don't have to deal with any bureaucracy sending my gun back.

I got my Classic Army P90 TR in the mail today. It doesn't come with a battery, and the mini-type battery I ordered is on it's way. Once the P90 was out of the box, my friend and I decided to test it to see if it works (I ordered from Revolution Airsoft, and their return policy is 7 days from your order - so I essentially have 3 days to return this if it's broken).

We plugged in his 8.4v NiMh AK stick-type battery into the P90 and pulled the trigger. It made a pathetic 'weh' sound. Then the P90 went totally silent and the battery began to rapidly overheat. We removed the battery promptly. His battery never overheats instantly like that. We put it back in his AK and it worked fine. The battery cooled down and his gun operated flawlessly.

My brand new P90, however, remained silent. We tried the battery again a couple times, with the same result. The P90 simply didn't fire. It did nothing at all, on semi-auto and auto. The battery just overheated instantly, and the P90 did not move at all. No noise from the gearbox at all, no electrical sounds. It was as if there was no battery at all.

The only time it made any noise was that ONE time when we first plugged the battery in.

I have read almost every single P90 thread on this forum, and all of them said the P90 is compatible with every battery type (the issue is fitting the batteries in the stock).

So have I missed something? Were we just being idiots? Have we shorted out the motor? Or should I just wait and plug in the mini-type when it arrives and hope the thing works?

My issue is I only have 3 days to determine if the gun is truly broken - after that, the return policy expires :c

Any help or advice would be greatly appreciated!

[Sep II]

Dang. I made sure it was the Proline version, not the crap Sportline one too...

The only P90's that are available to me at this time are the CA Proline versions, and the King Arms one. Of the around 20-odd reviews I read across the interwebs, the bias was towards getting a CA Proline version simply by virtue of their solid full-metal gearboxes.

The amount of literature regarding all the P90 variants I read up on all had a similar theme: each brand of P90 was good, but each had one unique flaw... so essentially I ended up having to pick the lesser evil, lol

[Sep II]

Ah! Ok, just got in contact with a GunDoc... they said the battery simply wasn't strong enough. We used a 8.4v... apparently we need to use a 9.6v battery.

So now I will try and find a 9.6v battery and see if this solves the problem...

[lurkingknight]

I am not convinced. the 8.4 should still be able to turn the motor over. In fact it was able to do it once already.

Inspect the fuse. Beyond that, you risk voiding the warranty on it if you remove the gearbox to do a wire inspection. If you decide to inspect the wiring, the good thing about the p90 is that only 2 screws hold the gearbox in, and all the wiring is external on the gearbox, so you should be able to see if there is a short somewhere.

[Sep II]

Good thinking, we'll check out the fuse...

...

Inspected the fuse - it's fine. Fuse is intact, nothing out of the ordinary around the wiring either. Perhaps the battery had just enough residual charge to let out a half-cycle when we connected it up this morning. It makes sense the battery instantly overheated - it would've been straining trying to push those internals.

Although I could be wrong. Anyone know of anyone who is running a CA90 TR PROline with a battery that is less than 9.6v?

The only other explanations for this problem I can think of would be either 1, the motor is dead, or 2, someone filled the gearbox with glue. Also, I should have clarified (and have edited the original post) - the gun did NOT fire completely the first time, it simply made a noise. No air was discharged from the barrel. I apologise for the confusion (I was very tired this morning, lol).

[Short Round]

Maybe the 8.4v is on the frits? Have you tried another battery?

[iKliiu]

The stock spring is quite stiff, and the motor doesn't have that much torque, especially with a 8.4V mini. Try a 9.6V or a 7.4V LiPo and if that doesn't work, you should look at the gearbox.

[Sep II]

Najohn! I read your guide during my research process - bloody hell it's a brilliant guide! Thank you so much for that!

Anyways, my friend's 8.4v NiMh battery is just fine - it works in his AK quite well with no issues. Unfortunately, I'm still waiting on the 9.6v NiMh to arrive in the mail.

The moment of truth will arrive when I can test this thing with different batteries - if the 9.6v solves the problem, great! If not, well... I'll likely be past the return date by then, so I'll probably end up cracking the thing open and ordering the replacement part of whatever is defective.

[Sep II]

Also thanks for that tidbit, iKliiu. Of all the disassembly vids and reviews I saw, the stiff spring was a common element. I may end up replacing the spring eventually so the motor isn't overworked. It may help increase the longevity of the gun in the long term.

[iKliiu]

I owned a CA90 Proline too, and my spare 8.4v didn't pull the gearbox when it was stock (highly modified now). I use LiPos, and both my 7.4V and 11.1V pulled the stock spring with the original motor too.

[Sep II]

How does your P90 fare now, with the modifications? Also, how did it do when it was stock?

[iKliiu]

Now, it shoots roughly 40 RPS at 363 plus/minus 2 FPS. Can hit a target at 200 feet. I didn't test it out much stock, but it was shooting around 20ish RPS with the same battery.

[Styrak]

It all depends on the spring in the gun. Of course it can run a different gun fine, it has a different spring.

[Sep II]

Thanks for the feedback so far, guys - I really appreciate it!

Once the 9.6v NiMh mini battery comes in, I'll let everyone know if it has solved the problem or not and I can put this thread to rest as a note to anyone buying a new CA90. If worse comes to worst, hopefully all I'll have to do is swap out the spring. Let's hope it's nothing more complicated than that! Otherwise, woooo, bye-bye money...

In the meantime, suggestions and possible solutions I may have overlooked are still welcome!

[Curo]

I have a 8.4v as a back up and it barely was able to turn my gun with a CQB spring the ROF went down, but allot like from roughly 800rpm to around 450rpm.