problem with a small cooler

[corvairbob]

hi. I'm new to this group and to help save time in a search i would like to see if one of you have an answer to this problem?
I'm taking a refrigeration class and the instructor gave me this problem to try and solve. here is the problem. i thing the answer is a plugged capillary tube but lets see if any of you ave a different answer?
here is the scenario. i have this cooler that takes 134a 16 oz charge. when i first turned it on the compressor failed to start. i changes the starter with a knowned good one. still the same. i connected the gage set and the reading were 95 hs 57 ls when the motor tries to start it draws 28 amps. i then took a pipe and hit the side of the compressor it started. the pressure went to 195 hs 14 ls the after 15 min 170 hs 10 ls then 150 hs 10 ls. sometimes the compressor stops and starts like 20 seconds or so. it may restart and then may not.

any ideas? i tried to measure the voltage but my meter was broken. kids in the day class at work. but i did have voltage at the starter and the outside tas when the motor stopped so i don't think the problem is electrical. the condenser does get warm and the suction gets cold and it gets cold in the unit but i don't have that temp only by feel. thanks for any ideas or help. bob p.

[FEISTY]

First things first, corvairbob. Welcome to the group. Great bunch of techs, some who have forgotten more than most of us will ever know. Now, on to your question. You catch a break for being a student of the trade. You cannot look for any problem if your tools don't work. Spare batteries, extra manifold, just back up the basic items. Next...beating on the body sometimes will shake loose a stuck compressor. Taking amp draw first, pull wiring from comp. and check continuity of posts and possible grounding internally. When you can afford it, a testing tool called a hermetic analyzer is very helpful. Good one will test several different problems along with letting you try and start the body without using the original start components. Try to avoid being a " parts changer " before you know what the problem is and why the part[s] failed. You look better and customer will use you again if you save them money. If compressor stuck once, bet your paycheck it will again. You can put on a " hard start kit " if you diagnose it right to give it an extra boost but let customer know it is last fix before replacement. So.....take your time...look at everything...and remember...just because the lightbulb is out doesn't mean you re-wire the house !! Good luck. Someone is always here to help.